Owing to people pay much attention to the drinking water of daily life, the purchasing rate for the Reverse Osmosis Membrane (RO) water treatment unit of household is constantly soaring. As a result, the selling volume in the market is directly reflected in increasing manner. Accordingly, for the purpose of increasing production quantity and decreasing assembly laboring cost, manufacturers of the RO water treatment unit convert the traditional tube/pipe fittings of threaded type with much more labor hours in the plumbing task into tube/pipe fittings of inserting type with less labor hours in the plumbing task. According to current status, the plumbing task for the tube/pipe fittings of threaded type takes three seconds while the plumbing task for the tube/pipe fittings of inserting type only takes one second. Thus, the labor hours for the former is triple of the labor hours for the later.
The structure of the conventional tube/pipe fittings of inserting type is shown as in the FIGS. 1 through 8, which comprises a pipe fitting of elbow type 10, a sealing O-ring 20, an annular cooperative bushing collar 30, a cylindrical elastic sleeving collet 40 and an accessory latching clip 50 with a cantilevered lug, wherein:
Said pipe fitting of elbow type 10, which is unitarily extruded in one piece by plastics molding into tubular L-shaped fitting with two coupling unions 11 (FIG. 2) or tubular T-shaped fitting with three coupling unions 11 (FIG. 3), includes a hollow water passage 12, a cylindrical retainer 13 and a cylindrical docking receptacle 14 such that one coupling union 11 encloses the cylindrical retainer 13 therein while the circumferences of the rest coupling unions 11 have male threads formed thereon, and the cylindrical docking receptacle 14 runs through the cylindrical retainer 13 in communicable with the hollow water passage 12;
Said sealing O-ring 20 is made of rubber to be inserted against the inner bottom wall of the cylindrical retainer 13 in the pipe fitting of elbow type 10 such that whose outer diameter equals the inner diameter of the cylindrical retainer 13 in the pipe fitting of elbow type 10 while whose inner diameter is slightly less than the inner diameter of the cylindrical docking receptacle 14 in the pipe fitting of elbow type 10;
Said annular cooperative bushing collar 30, which is unitarily extruded in one piece by plastics molding into two-stair tiered hollow cylinder to be partially slid into the coupling union 11 on the cylindrical retainer 13 of the pipe fitting of elbow type 10 by means of glue-bonding or high frequency melt-bonding method, includes a top surface 31, a bottom surface 32, a jointing circular through-hole 33 running through the top surface 31 and bottom surface 32, and a guiding conical flare 34 respectively created along each rim of the top surface 31 and bottom surface 32 such that the outer diameter of top stair rim abutting top surface 31 is greater than the outer diameter of bottom stair rim abutting bottom surface 32 (FIG. 4);
Said cylindrical elastic sleeving collet 40, which is unitarily extruded in one piece by plastics molding into hollow cylinder to be slid into the jointing circular through-hole 33 of the annular cooperative bushing collar 30, includes a peripheral gorgerin 43 integrating a top surface 41 and a bottom surface 42 with a circular sliding through hole 44 running through therein, an annular cambered locking flange 45 abutting the bottom surface 42 and an annular delimiting flange 46 abutting the top surface 41 as well as a plurality of longitudinal hooping slits 47 of circumferentially equivalent-space created along the bottom surface 42 towards the top surface 41 to be communicable with the circular sliding through hole 44, and a plurality of elastic griping ribs 48 of circumferentially equivalent-space created between two adjacent longitudinal hooping slit 47, wherein the outer diameter d1 of the peripheral gorgerin 43 is smaller than the inner diameter d2 of the jointing circular through-hole 33 in the annular cooperative bushing collar 30, the outer diameter d3 of the annular cambered locking flange 45 is greater than the inner diameter d2 of the jointing circular through-hole 33 in the annular cooperative bushing collar 30 and the outer diameter d4 of the annular delimiting flange 46 is greater than the inner diameter d3 of the annular cambered locking flange 45 (FIGS. 4 and 6); and
Said accessory latching clip 50, which is unitarily extruded in one piece by plastics molding into planiform collar to be served as clamping means for assembled pipe fitting, includes a U-shaped nick 51 with two prongs of straight legs encompassing central cut nick such that the width h between two legs of the U-shaped nick 51 is slightly greater than the outer diameter d1 of the peripheral gorgerin 43 in the cylindrical elastic sleeving collet 40 (FIG. 8).
Please further refer to FIGS. 9 through 13. The assembling steps of the foregoing conventional tube/pipe fittings of inserting type are shown as below.
a. Insert the sealing O-ring 20 into the cylindrical retainer 13 in the pipe fitting of elbow type 10 to the thorough end such that the sealing O-ring 20 contacts against the inner bottom wall of the cylindrical retainer 13 (FIGS. 10 and 11).
b. Facing the bottom surface 32 of the annular cooperative bushing collar 30 towards the cylindrical retainer 13 of the pipe fitting of elbow type 10, insert the annular cooperative bushing collar 30 into the cylindrical retainer 13 of the pipe fitting of elbow type 10 (FIG. 11), then securely fix the annular cooperative bushing collar 30 onto the coupling union 11 of the pipe fitting of elbow type 10 by means of glue-bonding or high frequency melt-bonding method (FIG. 12).
c. Facing the bottom surface 42 of the cylindrical elastic sleeving collet 40 towards the jointing circular through-hole 33 of the annular cooperative bushing collar 30, forcibly push the annular cambered locking flange 45 of the cylindrical elastic sleeving collet 40 forwardly to pass it through the jointing circular through-hole 33 of the annular cooperative bushing collar 30 to finish the assembly of the conventional tube/pipe fittings of inserting type (FIGS. 9 and 13). At this moment, a clearance G1 is created because the outer diameter d1 of the peripheral gorgerin 43 in the cylindrical elastic sleeving collet 40 is less than the inner diameter d2 of the jointing circular through-hole 33 in the annular cooperative bushing collar 30 (FIG. 13 and associated partially magnified view) so that the cylindrical elastic sleeving collet 40 is free to move to and fro in the jointing circular through-hole 33 of the annular cooperative bushing collar 30 without possibility for the cylindrical elastic sleeving collet 40 being slipped out of the annular cooperative bushing collar 30 under the confinement of the annular cambered locking flange 45 because the outer diameter d3 of the annular cambered locking flange 45 in the cylindrical elastic sleeving collet 40 is greater than the inner diameter d2 of the jointing circular through-hole 33 in the annular cooperative bushing collar 30.
Please refer to FIGS. 14 through 18, 14-a and 15-a. The mutually jointing steps between the foregoing conventional tube/pipe fittings of inserting type and the water tube/pipe are shown as below.
A. Align and insert a water tube/pipe T into the circular sliding through hole 44 in the top surface 41 of the cylindrical elastic sleeving collet 40 (FIG. 14), then force the water tube/pipe T orderly pass through the circular sliding through hole 44 of the cylindrical elastic sleeving collet 40 and the inner bore of the sealing O-ring 20 up to the cylindrical docking receptacle 14 of the pipe fitting of elbow type 10 (FIG. 15). At this moment, the water tube/pipe T is firmly sleeved by the elastic griping ribs 48 of the circular sliding through hole 44 in the cylindrical elastic sleeving collet 40, and the sealing O-ring 20 is under symmetrically isometric deformed by the compressing force F1 caused by the outer wall of the water tube/pipe T so that a leakage-free effect due to close contact between the water tube/pipe T and the cylindrical docking receptacle 14 of the pipe fitting of elbow type 10 is created, wherein (FIG. 15-a) is a cross sectional view showing a symmetrically isometric deformation 22 of the sealing O-ring 20, which becomes oval shape, while (FIG. 14-a) is a cross sectional view showing no symmetrically isometric deformation 21 of the sealing O-ring 20, which is round shape.
B. hold exposed section of the water tube/pipe T outside of the cylindrical elastic sleeving collet 40, then pull it outwards along the top surface 41 of the cylindrical elastic sleeving collet 40 so that the cylindrical elastic sleeving collet 40 with annular delimiting flange 46 is simultaneously drawn outwards with a certain displacement due to securely clamping of the cylindrical elastic sleeving collet 40 onto the outer wall of the water tube/pipe T (FIG. 16). At this moment, the annular cambered locking flange 45 of the cylindrical elastic sleeving collet 40 is forced to glide into the guiding conical flare 34 of bottom stair rim abutting bottom surface 32 of the jointing circular through-hole 33 in the annular cooperative bushing collar 30 so that an enhanced clamping action of the cylindrical elastic sleeving collet 40 onto the outer wall of the water tube/pipe T is obtained because the annular cambered locking flange 45 is inwardly squeezed by the guiding conical flare 34. Thereby, the outwardly drawn annular delimiting flange 46 detaches off the annular cooperative bushing collar 30 to create a clearance G against the top surface 31 of the annular cooperative bushing collar 30 with same displacement as that of the cylindrical elastic sleeving collet 40 (FIG. 16 and associated partially magnified view).
C. Align the U-shaped nick 51 of the accessory latching clip 50 with the clearance G between the annular delimiting flange 46 of the cylindrical elastic sleeving collet 40 and the top surface 31 of the annular cooperative bushing collar 30, then thoroughly inset the accessory latching clip 50 up to the inner hemispherical bottom of the U-shaped nick 51 contacts against the peripheral gorgerin 43 of the cylindrical elastic sleeving collet 40 so that the cylindrical elastic sleeving collet 40 is tightly fixed in stable manner with no moving possibility to complete the mutually jointing procedure between the foregoing conventional tube/pipe fittings of inserting type and the water tube/pipe T (FIG. 17).
Please further refer to FIGS. 18, 19, 14-a, 15-a and 18-a. Because all parts related to Reverse Osmosis Membrane (RO) water treatment unit such as filter cartridge, Reverse Osmosis Membrane (RO) tube, plumbing fitting, plumbing tubes and so on must be mounted nearby the RO water treatment unit so that the spaces among all these parts must be closely arranged with bending water tube/pipe to effectively employ limited space confined by the RO water treatment unit.
If the water pipe/tube T is bent towards the opening of the U-shaped nick 51 in the accessory latching clip 50 by a bending force Fc (FIGS. 18 and 19), the annular delimiting flange 46 of the cylindrical elastic sleeving collet 40 is borne uneven stress from the water pipe/tube T, namely a partial section of the annular delimiting flange 46, which is corresponding to the opening of the U-shaped nick 51, will lose support from the accessory latching clip 50 and result in no counteraction to the bending force Fc. Accordingly, the peripheral gorgerin 43 is also borne uneven stress from the water pipe/tube T with result that a partial section of the peripheral gorgerin 43 in corresponding to the arrowhead of bending force Fc will closely contact with the inner wall of the jointing circular through-hole 33 while another partial section of the peripheral gorgerin 43 in opposed to the arrowhead of bending force Fc will detach the inner wall of the jointing circular through-hole 33 to create a gap G2 (FIG. 18 and associated partially magnified view). Thereby, due to the bent water pipe/tube T, the deformation of the sealing O-ring 20 will be changed from original symmetrically isometric deformation 22 (FIG. 15-a) into undesired asymmetrically non-isometric deformation 23, 24 (FIG. 18-a).
In other words, the deformation of a partial section of the sealing O-ring 20 in corresponding to the arrowhead of bending force Fc will be increased as shown in asymmetrically non-isometric deformation 23 (FIG. 18-a) while the deformation of another partial section of the sealing O-ring 20 in opposed to the arrowhead of bending force Fc will be decreased as shown in asymmetrically non-isometric deformation 24 (FIG. 18-a). Thus, the sealing effect of the sealing O-ring 20 over the outer wall of the water pipe/tube T becomes defectively uneven. For comparison of sealing effect in efficiency order, the asymmetrically non-isometric deformation 23 is better than the symmetrically isometric deformation 22 while the symmetrically isometric deformation 22 is better than the asymmetrically non-isometric deformation 24. Under normal water pressure of exceeding 80 psi in the water pipe/tube T of general RO water treatment unit with degraded plastics parts from aging effect incurred by the hot expansion and cold shrinkage of the seasonal temperature fluctuation, the compressed water P in the water pipe/tube T will seep out via partial section of bad sealing effect between the outer wall of the water pipe/tube T and the bad deformation of the sealing O-ring 20 like the asymmetrically non-isometric deformation 24 in FIG. 18-a. Consequently, the seeping compressed water P will leak out of the cylindrical elastic sleeving collet 40 via the circular sliding through hole 44 of the cylindrical elastic sleeving collet 40 and gradually spread over the circuit cabling or compressed pump of the RO water treatment unit to damage the overall RO water treatment unit into functionless manner, or even worse to cause safety accident due to electric leakage. All such serious results are incurred by the leakage drawback in the water pipe/tube fitting of quick connection. Therefore, how to solve the leakage drawback in the water pipe/tube fitting of quick connection becomes an urgent issue for the manufacturers of the RO water treatment unit.